The Victoria's Secret model and the 'Lord Of The Rings' actor became parents to son Flynn last January and Miranda says it's wonderful to see Orlando bonding with their boy.
She said: "He has really stepped up to the role and is very hands-on. It makes me proud that he is such a good dad."
Little Flynn celebrated his first birthday on January 6 and during his party he got to taste cake for the very first time.
Miranda told People: "It was the first cake he had ever seen or tasted. It was a gluten-free cake and organic, of course. He put his face in the cake. It was a healthy kick-start to his first birthday."
"There were a lot of balloons. We had a balloon man come because Flynn likes balloons. That was a lot of fun."
However, the party - which was attended by five of Flynn's "little friends" - left the birthday boy exhausted and he had to be put down for some much-needed rest.
Miranda said: "He was awake for a couple of hours and then it was nap time."